A Self-Adapting and Efficient Dandelion Algorithm and Its Application to Feature Selection for Credit Card Fraud Detection

A dandelion algorithm(DA) is a recently developed intelligent optimization algorithm for function optimization problems. Many of its parameters need to be set by experience in DA,which might not be appropriate for all optimization problems. A self-adapting and efficient dandelion algorithm is proposed in this work to lower the number of DA's parameters and simplify DA's structure. Only the normal sowing operator is retained;while the other operators are discarded. An adaptive seeding radius strategy is designed for the core dandelion. The results show that the proposed algorithm achieves better performance on the standard test functions with less time consumption than its competitive peers. In addition, the proposed algorithm is applied to feature selection for credit card fraud detection(CCFD), and the results indicate that it can obtain higher classification and detection performance than the-state-of-the-art methods.

A Credit Card Fraud Detection Model Based on Multi-Feature Fusion and Generative Adversarial Network

Credit Card Fraud Detection(CCFD)is an essential technology for banking institutions to control fraud risks and safeguard their reputation.Class imbalance and insufficient representation of feature data relating to credit card transactions are two prevalent issues in the current study field of CCFD,which significantly impact classification models’performance.To address these issues,this research proposes a novel CCFD model based on Multifeature Fusion and Generative Adversarial Networks(MFGAN).The MFGAN model consists of two modules:a multi-feature fusion module for integrating static and dynamic behavior data of cardholders into a unified highdimensional feature space,and a balance module based on the generative adversarial network to decrease the class imbalance ratio.The effectiveness of theMFGAN model is validated on two actual credit card datasets.The impacts of different class balance ratios on the performance of the four resamplingmodels are analyzed,and the contribution of the two different modules to the performance of the MFGAN model is investigated via ablation experiments.Experimental results demonstrate that the proposed model does better than state-of-the-art models in terms of recall,F1,and Area Under the Curve(AUC)metrics,which means that the MFGAN model can help banks find more fraudulent transactions and reduce fraud losses.

A Credit Card Fraud Model Prediction Method Based on Penalty Factor Optimization AWTadaboost

With the popularity of online payment, how to perform creditcard fraud detection more accurately has also become a hot issue. And withthe emergence of the adaptive boosting algorithm (Adaboost), credit cardfraud detection has started to use this method in large numbers, but thetraditional Adaboost is prone to overfitting in the presence of noisy samples.Therefore, in order to alleviate this phenomenon, this paper proposes a newidea: using the number of consecutive sample misclassifications to determinethe noisy samples, while constructing a penalty factor to reconstruct thesample weight assignment. Firstly, the theoretical analysis shows that thetraditional Adaboost method is overfitting in a noisy training set, which leadsto the degradation of classification accuracy. To this end, the penalty factorconstructed by the number of consecutive misclassifications of samples isused to reconstruct the sample weight assignment to prevent the classifierfrom over-focusing on noisy samples, and its reasonableness is demonstrated.Then, by comparing the penalty strength of the three different penalty factorsproposed in this paper, a more reasonable penalty factor is selected.Meanwhile, in order to make the constructed model more in line with theactual requirements on training time consumption, the Adaboost algorithmwith adaptive weight trimming (AWTAdaboost) is used in this paper, so thepenalty factor-based AWTAdaboost (PF_AWTAdaboost) is finally obtained.Finally, PF_AWTAdaboost is experimentally validated against other traditionalmachine learning algorithms on credit card fraud datasets and otherdatasets. The results show that the PF_AWTAdaboost method has betterperformance, including detection accuracy, model recall and robustness, thanother methods on the credit card fraud dataset. And the PF_AWTAdaboostmethod also shows excellent generalization performance on other datasets.From the experimental results, it is shown that the PF_AWTAdaboost algorithmhas better classification performance.

Credit Card Fraud Detection on Original European Credit Card Holder Dataset Using Ensemble Machine Learning Technique

The proliferation of digital payment methods facilitated by various online platforms and applications has led to a surge in financial fraud,particularly in credit card transactions.Advanced technologies such as machine learning have been widely employed to enhance the early detection and prevention of losses arising frompotentially fraudulent activities.However,a prevalent approach in existing literature involves the use of extensive data sampling and feature selection algorithms as a precursor to subsequent investigations.While sampling techniques can significantly reduce computational time,the resulting dataset relies on generated data and the accuracy of the pre-processing machine learning models employed.Such datasets often lack true representativeness of realworld data,potentially introducing secondary issues that affect the precision of the results.For instance,undersampling may result in the loss of critical information,while over-sampling can lead to overfitting machine learning models.In this paper,we proposed a classification study of credit card fraud using fundamental machine learning models without the application of any sampling techniques on all the features present in the original dataset.The results indicate that Support Vector Machine(SVM)consistently achieves classification performance exceeding 90%across various evaluation metrics.This discovery serves as a valuable reference for future research,encouraging comparative studies on original dataset without the reliance on sampling techniques.Furthermore,we explore hybrid machine learning techniques,such as ensemble learning constructed based on SVM,K-Nearest Neighbor(KNN)and decision tree,highlighting their potential advancements in the field.The study demonstrates that the proposed machine learning models yield promising results,suggesting that pre-processing the dataset with sampling algorithm or additional machine learning technique may not always be necessary.This research contributes to the field of credit card fraud detection by emphasizing the potential of employing machine learning models directly on original datasets,thereby simplifying the workflow and potentially improving the accuracy and efficiency of fraud detection systems.

Credit Card Fraud Detection Using Weighted Support Vector Machine

Credit card fraudulent data is highly imbalanced, and it has presented an overwhelmingly large portion of nonfraudulent transactions and a small portion of fraudulent transactions. The measures used to judge the veracity of the detection algorithms become critical to the deployment of a model that accurately scores fraudulent transactions taking into account case imbalance, and the cost of identifying a case as genuine when, in fact, the case is a fraudulent transaction. In this paper, a new criterion to judge classification algorithms, which considers the cost of misclassification, is proposed, and several undersampling techniques are compared by this new criterion. At the same time, a weighted support vector machine (SVM) algorithm considering the financial cost of misclassification is introduced, proving to be more practical for credit card fraud detection than traditional methodologies. This weighted SVM uses transaction balances as weights for fraudulent transactions, and a uniformed weight for nonfraudulent transactions. The results show this strategy greatly improve performance of credit card fraud detection.

Credit Card Fraud Detection Based on Machine Learning

In recent years,the rapid development of e-commerce exposes great vulnerabilities in online transactions for fraudsters to exploit.Credit card transactions take a salient role in nowadays’online transactions for its obvious advantages including discounts and earning credit card points.So credit card fraudulence has become a target of concern.In order to deal with the situation,credit card fraud detection based on machine learning is been studied recently.Yet,it is difficult to detect fraudulent transactions due to data imbalance(normal and fraudulent transactions),for which Smote algorithm is proposed in order to resolve data imbalance.The assessment of Light Gradient Boosting Machine model which proposed in the paper depends much on datasets collected from clients’daily transactions.Besides,to prove the new model’s superiority in detecting credit card fraudulence,Light Gradient Boosting Machine model is compared with Random Forest and Gradient Boosting Machine algorithm in the experiment.The results indicate that Light Gradient Boosting Machine model has a good performance.The experiment in credit card fraud detection based on Light Gradient Boosting Machine model achieved a total recall rate of 99%in real dataset and fast feedback,which proves the new model’s efficiency in detecting credit card fraudulence.

Dynamic Programming for Estimating Acceptance Probability of Credit Card Products

Banks have many variants of a product which they can offer to their customers. For example, a credit card can have different interest rates. So determining which variants of a product to offer to the new customers and having some indication on acceptance probability will aid with the profit optimisation for the banks. In this paper, the authors look at a model for maximisation of the profit looking at the past information via implementation of the dynamic programming model with elements of Bayesian updating. Numerical results are presented of multiple variants of a credit card product with the model providing the best offer for the maximum profit and acceptance probability. The product chosen is a credit card with different interest rates.

Profitable credit card business empirical analysis of factors

Since 1995, major domestic commercial banks are beginning to have a variety of credit cards issued. However, at present, China＇s relatively low profitability of the credit card business, it accounts for a smaller proportion of total bank income. By means of credit card revenue／cost structure analysis, the authors found spending and overdraft balances affecting credit card business, an important factor in profitability. At the same time, combined with a commercial bank＇s existing statistical data, using SPSS software correlation and regression analysis, the authors found that the key to improve the bank card revenue is to raise China＇s commercial banks, credit card revolving credit utilization, and expand the scale of overdraft balances.

Predicting Credit Card Transaction Fraud Using Machine Learning Algorithms

Credit card fraud is a wide-ranging issue for financial institutions, involving theft and fraud committed using a payment card. In this paper, we explore the application of linear and nonlinear statistical modeling and machine learning models on real credit card transaction data. The models built are supervised fraud models that attempt to identify which transactions are most likely fraudulent. We discuss the processes of data exploration, data cleaning, variable creation, feature selection, model algorithms, and results. Five different supervised models are explored and compared including logistic regression, neural networks, random forest, boosted tree and support vector machines. The boosted tree model shows the best fraud detection result (FDR = 49.83%) for this particular data set. The resulting model can be utilized in a credit card fraud detection system. A similar model development process can be performed in related business domains such as insurance and telecommunications, to avoid or detect fraudulent activity.

Women And Credit Cards

Two men were getting ready to leave a pub. 'You can’t livewith them and you can’t live without them, 'one of the mengrumbled. 'That’s the way women are, pal,' agreed the other.'Who said anything about women?' snarled the first fellow. 'I’mtalking about credit cards. '

基于逻辑回归的个人信用评分卡模型研究

构建有效的个人信用风险评价系统,用以应对潜在的个人信贷风险,这对金融行业和社会公众皆有重要的现实意义。文章首先对数据进行清洗、预处理,然后通过WOE编码分箱、IV值进行变量筛选,构建了逻辑回归模型并基于逻辑回归模型建立了个人信用评分卡模型,该模型可辅助决策者制定合理的授信政策、定价策略以及其他相关业务运营策略。

建行信用卡系统全栈国产化改造研究

信用卡业务是业务逻辑最复杂的银行业务之一,其对可用性、可靠性、处理性能要求较高。从技术发展角度来看,多技术栈融合的新型IT架构,符合云计算资源池化的趋势。从业务角度来看,为满足不同的业务需求,同样存在多技术栈融合架构的诉求。然而,多计算架构并非简单实现一个全新的技术栈即可,需要解决架构改造与设计、系统验证、兼容性以及故障切换等一系列问题。面对上述挑战,该文面向金融IT系统高并发、高性能以及高可用需求,介绍了建行面向金融行业的高性能、高可用和高安全可靠的x86、ARM双平台混合架构系统中的设计与思考。通过一系列的代码迁移、应用迁移以及系统垂直优化技术,实现高性能、高可用和高安全的诉求,并在建行得到了大规模、长时间的真实系统验证。

aLMGAN-信用卡欺诈检测方法

针对信用卡交易数据的不平衡重叠问题,提出一种基于生成对抗网络的端到端一类分类方法。提出一种基于PCA和T_SNE的混合数据降维方法,对清洗后的数据进行特征降维;将降维后的数据送入所提出的基于LSTM和aMLP的生成对抗网络(aLMGAN),提出一种基于闵可夫斯基距离(Minkowski distance)的损失函数(Min-loss)代替原始生成对抗网络中的交叉熵损失函数,对正常交易数据进行单类稳定训练,形成一种特殊特征模式,区分不属于该特征的异常数据。通过使用kaggle上两个真实的公共信用卡交易数据集进行实验,验证了aLMGAN算法的有效性。

冒用花呗行为定性之争:问题、本质及解释

互联网金融领域的刑事犯罪治理难题表现出消极的点面效应。围绕冒用花呗的行为定性,至少存在花呗的法律属性定位、机器能否被骗、机器如何被骗的分析难题。其一,对于花呗的法律属性,研究论证的瑕疵在于客观解释立场的缺失。根据客观解释立场,“其他金融机构”中的“其他”意表除了商业银行以外的可以发行信用卡的金融机构,花呗属于刑法意义上的信用卡。其二,关于机器能否被骗。机器不具有自我意识的认识桎梏不能说明机器不可以被骗,否则只会固化人机关系“二元认识论”的旧观念,故机器不能被骗的立场应当被摒弃。其三,关于机器如何被骗。在探讨人工智能作为诈骗对象时引入预设同意理论已成为学界共识,然而该理论的运用现状过于粗简,其不仅可以说明机器的处分意识来源,更能说明人机关系的一体化。冒用花呗的行为定性中,关键特征是“人机交互的一体关系”,机器是自然人的电子代理人,人所排斥之事项即为机器所排斥之事项。第三方支付对于冒用者的身份要素陷入了错误认识,进而导致被害人财产受损。冒用花呗的行为应当定性为信用卡诈骗罪。

基于图注意力Transformer神经网络的信用卡欺诈检测模型

针对现有模型无法精准识别复杂多变的团伙诈骗模式的问题,提出一种新型实用的基于复杂交易图谱的信用卡反欺诈检测模型。首先,利用用户原始的交易信息构造关联交易图谱;随后,使用图自注意力Transformer神经网络模块直接从交易网络中挖掘团伙欺诈特征,无需构建繁冗的特征工程;最后,通过欺诈预测网络联合优化图谱中的拓扑模式和时序交易模式,实现对欺诈交易的高精度检测。在信用卡交易数据上的反欺诈实验结果表明,所提模型在全部评价指标上均优于7个对比的基线模型:在交易欺诈检测任务中,平均精度(AP)比基准图注意力神经网络(GAT)提升了20%,ROC曲线下方面积(AUC)平均提升了2.7%,验证了所提模型在信用卡欺诈交易检测中的有效性。

基于注意力机制优化的WGAN-BiLSTM信用卡欺诈检测方法

信用卡欺诈是银行操作风险的主要来源之一,对信用卡诈骗交易进行准确的检测对于减少银行经济损失具有重要意义。针对信用卡欺诈检测中存在的数据类别不平衡和数据漂移的问题,提出一种基于注意力机制优化的WGAN-BiLSTM信用卡欺诈检测方法。首先引入Wasserstein距离改进生成对抗网络(GAN),将信用卡数据输入至WGAN(Wasserstein GAN)中,在生成器和判别器相互博弈训练下,得到符合目标分布的欺诈样本;然后,构建结合注意力机制的双向长短期记忆(BiLSTM)网络,在正反两个方向上提取信用卡数据的长时依赖关系;最后,通过Softmax层输出分类结果。在欧洲持卡人数据集上的实验结果表明,所提方法能有效提升信用卡欺诈检测效果。

基于SMOTEENN-XGBoost的信用卡风险客户预测

为了实现信用卡的风险管控,降低因信用卡违约造成的经济损失,构建有效的信用卡风险预测模型尤为重要。针对信用卡数据分布不均衡的问题,使用ENN算法对经典SMOTE算法进行改进,构建了基于SMOTEENN-XGBoost的信用卡风险预测模型。实验表明,该模型的预测准确率能达到91.8%、AUPRC值为0.903,显著优于SVC、GBDT、AdaBoost等经典模型,对于信用不良信用卡用户的预测、帮助银行准确甄别客户信用风险具有重要价值。

基于XGBoost与LR融合模型的信用卡欺诈检测

随着银行卡业务的不断发展,各种各样的信用卡欺诈方式已经给金融机构带来严重的威胁,使得信用卡欺诈检测成为一个十分紧迫的任务。为解决此问题,提出一种XGBoost与LR融合模型。该模型首先运用XGBoost算法自动进行特征组合和离散化,然后将新构造的特征向量运用在逻辑回归LR模型上,通过XGBoost与LR融合模型进行分类预测。实验结果表明,与经典传统算法相比,提出的XGBoost与LR融合模型具有更好的欺诈检测性能,提高了信用卡欺诈检测的准确率。

基于改进SMOTE算法和深度学习集成框架的信用卡欺诈检测

当前机器学习(ML)算法已经被广泛用于信用卡欺诈检测。然而持卡人线上购物的动态性,以及正常和欺诈交易数据严重不平衡问题,影响了分类器的检测精度。为此,提出了基于深度学习集成框架的信用卡欺诈检测方法。首先,通过改进的合成少数类过采样(SMOTE)算法,解决信用卡数据集中欺诈交易和正常交易数量严重不平衡问题。其次,构建堆栈式深度学习集成框架,使用双向长短时记忆网络(Bi-LSTM)和门控循环单元(GRU)作为基础分类器,并通过多层感知机(MLP)作为元分类器,结合集成学习和深度学习的优点提高信用卡欺诈检测率。在公开数据集上的实验结果表明,所提深度学习集成方法与改进SMOTE算法相结合,分别实现了99.57%和99.82%的灵敏度和特异性结果,优于其他先进的信用卡欺诈检测算法。